SEOUL (AFP) - North Korea posted a new propaganda video on Friday, showing paratroopers descending on Seoul in an invasion scenario that it said would see thousands of US citizens living in South Korea taken hostage.

The four-minute video, titled "A Short, Three-Day War," begins with images of a massive artillery and rocket barrage, followed by a large-scale land and air assault with North Korean troops streaming over the border.

The video was posted on the North's official website, Uriminzokkiri, which distributes news and propaganda from the state media.

It comes at a time of escalating tensions on the Korean peninsula, with multiple threats from North Korea of an armed response to joint South Korea-US military drills and to UN sanctions imposed after its nuclear test last month.

On Thursday, the North Korean military threatened strikes on US military bases in Japan and Guam.

The video's male narrator describes different stages of the invasion, including the destruction of forces under the US Pacific Command with "powerful weapons of mass destruction".

"The crack stormtroops will occupy Seoul and other cities and take 150,000 US citizens as hostages," the narrator said.

The video showed footage of paratroopers jumping from the sky superimposed over an aerial shot of the South Korean capital, with North Korean military helicopters hovering overhead.

The airborne troops would engage South Korean soldiers in the streets of Seoul, as 4,000 tanks and 3,000 armored vehicles sweep across the border and race to the capital, the narrator said.

South Korea has a large US expatriate population, as well as 28,000 US troops based in the country.

The video was the latest in a line of similarly-themed productions posted to the Uriminzokkiri channel.

An offering early last month showed New York in flames after an apparent missile attack, and another two weeks later depicted US soldiers and President Barack Obama burning in the flames of a nuclear blast.

And earlier this week, another video showed the dome of the US Capitol building in Washington exploding in a fireball.